Wednesday, April 16, 2014

Salamanders and Exurbanization

The following is guest post by Kevin McLeroy, a senior at Clemson University enrolled in Dr. Barrett's Creative Inquiry course focused on amphibian conservation.

After two months of participation in Clemson’s Creative
Inquiry project on salamanders, I have learned exactly how much work goes into
designing a research project. These first weeks spent on this project have been
dedicated to developing an understanding of why salamanders are important to
our ecosystems, how they can indicate the quality of the environment they live
in, and what effects humans can have on them.

Our group’s research, directed by Clemson University
graduate student Nathan Weaver, focuses on the effects of urbanization on the
populations of salamanders. Our weekly meetings have focused on other research
projects related to salamanders, such as what kind of stream habitats they
prefer, the effects of buffer zones around the streams they live in, and
effects of UV radiation on amphibian eggs. Reading and discussing these papers
not only gave us some background information about amphibian ecology, but they
also gave us an understanding of the details involved with designing a research
project. Besides the actual field research, you have to find your research
sites, get permission from landowners to use the sites, and make sure they are
suitable for your project.

The main reason that salamanders are so intriguing is their
ability to indicate the state of the environment. Salamanders are useful in
this regard because their skin, like most amphibians, is very permeable, which
means that chemicals from the surrounding environment will get into their
bodies more easily. In addition to their permeable skin, salamanders also live
8-10 years, so they can show the long term environmental history of their
habitat. Because salamanders live in aquatic habitats, they are directly
affected by changes in water temperature, depth, and pollution.

On March 1, 2014, our group went with Nathan to inspect some
of the field sites. Before the trip, Nathan used GIS to find first order
streams located within these exurban developments. It was an all-day adventure
spent driving around the Highlands, North Carolina area where a good amount of
the field sites are located and making sure they are suitable. Unfortunately
some of the sites we had planned to use were unavailable because they were
located on private roads. It was important to make these trips in advance of
our research because if the majority of the field sites were unsuitable, then
our research would not be credible.

Our first sampling trip did not go as we had planned. The
heavy rain in Highlands, North Carolina went on for most of the day, which
decreases the detectability of the salamanders. Because salamanders live in
aquatic habitats, they are more likely to hide in the event of rain as to not
be swept away by the current. However, we sampled one stream and found barely
any salamanders, but another stream we sampled yielded many Blue Ridge
Two-Lined Salamanders. These salamanders are better adapted to lower levels of
dissolved oxygen, so they persist in urbanized streams. However, the fact that
only one species was detected speaks to the lack of species diversity caused by
exurbanization.

Everyone has different ways of loving nature, and
increasingly more people are flocking to private mountain communities with
stunning views and beautiful golf courses. However, most people living in these
communities do not realize the impact that their homes are having on the
environment. These communities have changed the landscape, and we will see the
effects of this in the coming years.

For my personal project within the creative inquiry, I
wanted to focus on the direct effect that water quality would have on the
populations, but I have reconsidered and now want to address stream
composition. When these communities are built, actions are taken to alter the
direction of stream flow, which results in undercut banks, different stream bed
composition, and different vegetation around the bank. Since salamanders prefer
to live under rocks on the stream bed, I would like to see what effects the
redirection of streams has on the abundance of species.

I am excited for all of the future sampling trips and
continuing to learn more about the effects of exurbanization on salamanders!